H520 Motor Failure

[Logan]

I very recently purchased an H520 and went out into the field today to test the aircraft, the first real test that I have done with it. However, towards the end of my 2nd battery (~50% remaining), the transmitter gave a warning that the #5 motor had stopped and the aircraft was operating on only 4 motors, so initiated a return to home command, during which the aircraft successfully returned home. It was obvious that while landing, the #5 motor had indeed fully stopped and was not spinning. The remaining 5 motors appeared to be functioning normally.

After the aircraft had landed, i performed an inspection of all 6 motors, and found nothing unusual about the #5 motor, no dust, dirt, strange feeling, or apparent damage at all. Further, I then attempted to restart the aircraft, and all 6 motors started up normally, and I was able to successfully hover the aircraft at ~1-2' in altitude before landing it.

I packed up the aircraft and brought it back into the office for analysis, only to discover that for whatever reason, the flight log for the flight in question was not stored on the ST16S ground station. I was able to pull the BIN data flash logs off of the aircraft directly through mission planner, however I have not been able to successfully decode them to find out exactly what happened. The "Auto Analysis" and "Review a Log" tools in mission planner failed on these log files, so if anyone knows the best way to decode these, I'd appreciate it.

Has anyone else had this issue and know what caused it? I have reached out to customer support and have yet to hear back. While I am thankful that the aircraft is 5-motor safe, and there wasn't an accident, this is an extremely serious issue and one I will want to get resolved before using the aircraft further, especially before I use it live in front of any clients.

 

[PatR]

Makes things a little tough when adding the aircraft to your liability policy too...

 

[terrence davidson]

if you did not remove the files from the h520 craft . try this get q groundcrontrol it also works for the h520 infact st16s. datapilot is yuneec verson of q ground control. you will be able to down load the files from the aircraft to it and it saves the files as ulog that format is supported by uavtool box by tuna online

 

[terrence davidson]

glad to hear atleast you were able to land and fully shutdown. .

 

[Logan]

glad to hear atleast you were able to land and fully shutdown. .

Yeah me too, was definitely a pucker moment though. I have probably 500+ hrs of multirotor flight and this is the first time I've ever survived a motor or prop failure (quads are not so forgiving). However, still concerning that a company with the manufacturing volume of Yuneec would put out motors that would stop mid flight for any reason.

 

[Steve Carr]

Yeah me too, was definitely a pucker moment though. I have probably 500+ hrs of multirotor flight and this is the first time I've ever survived a motor or prop failure (quads are not so forgiving). However, still concerning that a company with the manufacturing volume of Yuneec would put out motors that would stop mid flight for any reason.

Pure speculation on my part, but the problem is often the ESC rather than the motor.

 

[PatR]

You're probably right. Every time I've lost a motor, including after a crash, it was the ESC as the failure point.

 

[Steve Carr]

Perhaps the Flight Controller will shut down that motor circuit if it detects a problem such as over or under current. That might allow the motor to start again later, but the fault will probably re-occur.

 

[IRIS]

I very recently purchased an H520 and went out into the field today to test the aircraft, the first real test that I have done with it. However, towards the end of my 2nd battery (~50% remaining), the transmitter gave a warning that the #5 motor had stopped and the aircraft was operating on only 4 motors, so initiated a return to home command, during which the aircraft successfully returned home. It was obvious that while landing, the #5 motor had indeed fully stopped and was not spinning. The remaining 5 motors appeared to be functioning normally.

After the aircraft had landed, i performed an inspection of all 6 motors, and found nothing unusual about the #5 motor, no dust, dirt, strange feeling, or apparent damage at all. Further, I then attempted to restart the aircraft, and all 6 motors started up normally, and I was able to successfully hover the aircraft at ~1-2' in altitude before landing it.

I packed up the aircraft and brought it back into the office for analysis, only to discover that for whatever reason, the flight log for the flight in question was not stored on the ST16S ground station. I was able to pull the BIN data flash logs off of the aircraft directly through mission planner, however I have not been able to successfully decode them to find out exactly what happened. The "Auto Analysis" and "Review a Log" tools in mission planner failed on these log files, so if anyone knows the best way to decode these, I'd appreciate it.

Has anyone else had this issue and know what caused it? I have reached out to customer support and have yet to hear back. While I am thankful that the aircraft is 5-motor safe, and there wasn't an accident, this is an extremely serious issue and one I will want to get resolved before using the aircraft further, especially before I use it live in front of any clients.

Can you let me know if you find the flight data as I had a complete loss of aircraft into the sea and no data for the flight on the ST16.

Cheers IRIS

 

[wings]

Makes things a little tough when adding the aircraft to your liability policy too...

Rather distressing to hear especially with the new H520.

 

[Steve Carr]

Most failures on a new aircraft happen in the first 60 minutes of operation. And failures happen with all aircraft regardless of the make, model or cost.

 

[Ddraiggoch]

Can you let me know if you find the flight data as I had a complete loss of aircraft into the sea and no data for the flight on the ST16.

Cheers IRIS

Was this the 520 or the 480?

The 480 you should have data on the SD card in the ST16 shouldn’t you?

 

[Steve Carr]

Was this the 520 or the 480?
The 480 you should have data on the SD card in the ST16 shouldn’t you?

The flight telemetry is stored in the ST16 on both the 480 and 520.

 

[Ddraiggoch]

The flight telemetry is stored in the ST16 on both the 480 and 520.

It is?
On the 520 do you have to select that option?

Still trying to digest the user manual

 

[IRIS]

After the new firmware update some of us have found that the tlogs are missing even when the the box was checked in the ST16.

 

[Ddraiggoch]

After the new firmware update some of us have found that the tlogs are missing even when the the box was checked in the ST16.

OMG!
You lost. 520 into the ocean?

My stomach is churning at the very notion!

 

[BobW55]

No matter what the outcome, I encourage to call Yuneec. If you do not bring the problem to their attention, a problem that could exist across the 520 line may get missed. Making a phone call, it will at least get logged, may not get fixed.
I too have to agree, a failed, or failing ESC maybe the culprit.

 

[Logan]

No matter what the outcome, I encourage to call Yuneec. If you do not bring the problem to their attention, a problem that could exist across the 520 line may get missed. Making a phone call, it will at least get logged, may not get fixed.
I too have to agree, a failed, or failing ESC maybe the culprit.

Thanks for the info, yes, I have already reached out to Yuneec, but haven't heard back yet. Very long waits on their phone line (> 1 hour) so I'm going the email route for now.

 

[Logan]

For those of you interested, I managed to get flight logs successfully off of the autopilot, and have published them at the below link. The first sign of error occurs right at 14:34 where it enters fault tolerant control, and then I give the RTL command at 14:55. I'm not sure if there is enough evidence in these flight logs to check the ESC failure hypothesis, but I would love to see what anyone else can divine from this information.

Flight Review

 

[Logan]

Can you let me know if you find the flight data as I had a complete loss of aircraft into the sea and no data for the flight on the ST16.

Cheers IRIS

Yes, I managed to get the flight data off of the aircraft, though not off of the controller. It is at the below link if you want to see.
Flight Review